CVE Intelligence

Vulnerabilidades de Traefik

🔔 Criar alerta RSS

CVEs publicadas que afetam produtos de Traefik: 51 registro(s), com severidade, exploração e correções.

Somente exploradas (KEV) →

CVE-2026-54762 Alta · 8.6 CWE-636 23/06/2026
Traefik Kubernetes Ingress NGINX provider fails open when auth-secret resolution fails
Traefik is an HTTP reverse proxy and load balancer. From 3.7.0-ea.1 until 3.7.5, there is a medium severity vulnerability in Traefik's Kubernetes Ingress NGINX provider that causes affected routes to fail open. When an Ingress explicitly enables BasicAuth or DigestAuth through the supported nginx.ingress.kubernetes.io/auth-type and auth-secret annotations, but the referenced auth Secret cannot be resolved or parsed, Traefik logs the resolution error, skips installing the authentication middleware, and still emits a router to the backend service. A route that operators intended to protect is therefore published to the data plane without its authentication control, allowing unauthenticated access to the backend. The trigger is an invalid or unresolved auth dependency — a missing, malformed, unreadable, or policy-denied Secret — rather than an intentionally unprotected route. This vulnerability is fixed in 3.7.5.
CVE-2026-54761 Alta · 7.1 CWE-284 23/06/2026
Traefik: Kubernetes Gateway crossProviderNamespaces bypass allows HTTPRoute outside the allowlist to expose internal Traefik services
Traefik is an HTTP reverse proxy and load balancer. Prior to 3.6.21 and 3.7.5, there is a high severity vulnerability in Traefik's Kubernetes Gateway provider affecting the crossProviderNamespaces allowlist. For HTTPRoute rules that declare multiple (WRR) backendRefs, Traefik evaluates the allowlist against the target backendRef.namespace instead of the route's own namespace. As a result, an HTTPRoute created in a namespace that is not allow-listed can reference a cross-provider TraefikService such as api@internal, dashboard@internal or rest@internal by pointing backendRef.namespace at an allow-listed namespace covered by a Gateway API ReferenceGrant, exposing internal Traefik services on the data plane. Exploitation requires the ability to create an accepted HTTPRoute and a matching ReferenceGrant from an allow-listed namespace; it does not require any change to Traefik static configuration, RBAC, or the deployment itself. This vulnerability is fixed in 3.6.21 and 3.7.5.
CVE-2026-53622 Crítica · 10.0 CWE-288 23/06/2026
Traefik: falha na seleção de configuração TLS do HTTP/3 contorna mTLS por router
Traefik é um proxy reverso HTTP e balanceador de carga. Versões anteriores a 3.7.3, 3.6.18 e 2.11.51 apresentam uma vulnerabilidade crítica na seleção de configuração TLS do HTTP/3 (QUIC) do Traefik, que permite que clientes não autenticados contornem a imposição de mTLS específica de router. Quando o HTTP/3 está habilitado em um entrypoint, o handshake TLS seleciona a configuração TLS aplicável por meio de uma busca exata e sensível a maiúsculas e minúsculas sobre o valor de SNI, que não corresponde a padrões de host com curinga (por exemplo, *.example.com) nem a variações de capitalização do hostname configurado. Como o handshake recorre à configuração TLS padrão, que pode não exigir certificados de cliente, um cliente pode concluir o handshake QUIC sem apresentar certificado, enquanto a camada de roteamento HTTP subsequente ainda encaminha a requisição para um backend protegido por uma política mTLS específica de router. O problema afeta implantações em que o HTTP/3 está habilitado, um router usa uma regra Host com curinga ou correspondência de hostname sem distinção de maiúsculas e minúsculas, um TLSOptions específico de router impõe autenticação por certificado de cliente, e o acesso UDP ao entrypoint é alcançável por um atacante. Esta vulnerabilidade está corrigida nas versões 3.7.3, 3.6.18 e 2.11.51.
CVE-2026-48491 Crítica · 10.0 CWE-288 23/06/2026
Bypass de mTLS via TLSOptions com wildcard no SNICheck do Traefik (CVE-2026-48491)
Traefik é um proxy reverso HTTP e balanceador de carga. Das versões 3.7.0 até 3.7.3, há uma vulnerabilidade de alta severidade na proteção contra domain fronting (SNICheck) do Traefik que permite a um cliente não autenticado contornar o mTLS imposto por TLSOptions de roteadores com wildcard. Quando um roteador usa uma regra de host com curinga, como Host(*.example.com), com opções TLS mais restritivas (por exemplo RequireAndVerifyClientCert), o SNICheck resolve as opções TLS para o cabeçalho Host HTTP usando apenas buscas exatas em mapa e nunca aplica correspondência por curinga. Se outro SNI permissivo estiver servido no mesmo entrypoint, um atacante pode completar o handshake TLS sob as opções permissivas e então enviar um cabeçalho Host HTTP apontando para o backend protegido por wildcard, alcançando-o sem apresentar certificado de cliente. Isso afeta o caminho HTTPS / HTTP-2 regular e não exige HTTP/3. Esta vulnerabilidade está corrigida na versão 3.7.3.
CVE-2026-48020 Crítica · 10.0 CWE-288 23/06/2026
Contorno de Autenticação no Middleware StripPrefix do Traefik (CVE-2026-48020)
O Traefik é um proxy reverso HTTP e balanceador de carga. Antes de 2.11.48, 3.6.19 e 3.7.3, há uma vulnerabilidade de alta severidade no middleware StripPrefix do Traefik que permite a um atacante não autenticado contornar a autenticação e a autorização no nível de rota. Quando um router público corresponde a uma regra PathPrefix e aplica o middleware StripPrefix, um caminho de requisição contendo .. ou sua forma codificada em percentual %2e%2e pode corresponder à rota pública no momento do roteamento e, depois que o prefixo é removido e o caminho é normalizado, resolver para um caminho servido por um router autenticado separado. Como resultado, um atacante pode alcançar caminhos protegidos do backend, como endpoints administrativos ou de configuração interna, sem satisfazer o middleware de autenticação anexado ao router protegido. Esta vulnerabilidade está corrigida nas versões 2.11.48, 3.6.19 e 3.7.3.
CVE-2023-54365 Alta · 7.5 CWE-400 23/06/2026
Traefik - Denial of Service via HTTP/2 Request Handling
Traefik before 2.10.5 and 3.0.0-beta4 is affected by a denial-of-service vulnerability in HTTP/2 request handling inherited from the Go standard library's HTTP/2 implementation (CVE-2023-44487 / CVE-2023-39325, the 'Rapid Reset' technique). A remote attacker can rapidly create and cancel HTTP/2 streams to exhaust server resources and cause service unavailability.
CVE-2026-44774 Crítica · 9.9 CWE-284 15/05/2026
Traefik: Gateway API TraefikService backend accepts rest@internal, allowing unauthorized exposure of the REST provider despite providers.rest.insecure=false
Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.46, 3.6.17, and 3.7.1, Traefik's Kubernetes Gateway API provider allows a tenant with HTTPRoute creation permissions to expose the REST provider handler, bypassing the providers.rest.insecure=false setting. The Gateway provider accepts any TraefikService backend reference whose name ends with @internal, making it possible to route traffic to rest@internal in addition to the intended api@internal. In shared Gateway deployments where the REST provider is enabled, this allows a low-privileged actor to gain live dynamic configuration write access to Traefik, enabling unauthorized reconfiguration of routers and services. This vulnerability is fixed in 2.11.46, 3.6.17, and 3.7.1.
CVE-2026-41181 Média · 5.8 CWE-201 15/05/2026
Traefik: Errors middleware forwards Authorization and Cookie headers to separate error page service
Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.44, 3.6.15, and 3.7.0-rc.3, there is an information disclosure vulnerability in Traefik's errors (custom error pages) middleware. When the backend returns a response matching the configured status range, the middleware forwards the original request's complete header set, including Authorization, Cookie, and other authentication material, to the separate error page service rather than only the minimal context needed to render the error page. This behavior is undocumented: the documentation states only that Host is forwarded by default, so operators are not warned that sensitive credentials are shared across service boundaries. Deployments using the errors middleware with a distinct error page service may inadvertently expose end-user credentials to infrastructure that was not intended to receive them. This vulnerability is fixed in 2.11.44, 3.6.15, and 3.7.0-rc.3.
CVE-2026-41263 Baixa · 3.7 CWE-208 30/04/2026
Traefik: BasicAuth middleware: timing side-channel vulnerability
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a timing side-channel vulnerability in Traefik's BasicAuth middleware that allows an attacker to enumerate valid usernames through response-time differences. The variable intended to hold a constant-time fallback secret always resolves to an empty string, causing the constant-time comparison to short-circuit in microseconds rather than performing a full bcrypt evaluation. This restores the original timing oracle and makes it possible to distinguish existing users from non-existing ones by measuring authentication response times. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.
CVE-2026-41174 Média · 6.4 CWE-653 30/04/2026
Traefik Kubernetes CRD allows unauthorized cross-namespace middleware binding
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a potential vulnerability in Traefik's Kubernetes CRD provider cross-namespace isolation enforcement. When providers.kubernetesCRD.allowCrossNamespace=false, Traefik correctly rejects direct cross-namespace middleware references from IngressRoute objects, but fails to apply the same restriction to middleware references nested inside a Chain middleware's spec.chain.middlewares[]. An actor with permission to create or update Traefik CRDs in their own namespace can exploit this to cause Traefik to resolve and apply middleware objects from another namespace, bypassing the documented isolation boundary. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.
CVE-2026-40912 Alta · 8.2 CWE-706 30/04/2026
Traefik: StripPrefixRegex auth bypass via Path/RawPath desync
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this dot-segment path in X-Forwarded-Uri, which does not match the protected path patterns and therefore allows the request through. The backend then normalizes the dot-segment to the real path per RFC 3986 and serves the protected content An unauthenticated attacker can exploit this against any backend that performs dot-segment normalization. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.
CVE-2026-39858 Crítica · 10.0 CWE-290 30/04/2026
Traefik: Forwarded alias spoofing top pre-auth decision bypass
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high severity authentication bypass vulnerability in Traefik's ForwardAuth and snippet-based authentication middleware. Traefik's forwarded-header sanitization logic targets only canonical header names (e.g., X-Forwarded-Proto) and does not strip or normalize alias variants that use underscores instead of dashes (e.g., X_Forwarded_Proto). These unsanitized alias headers are forwarded intact to the authentication backend. When the backend normalizes underscore and dash header forms equivalently, an attacker can inject spoofed trust context — such as a trusted scheme or host — through the alias headers and bypass authentication on protected routes without valid credentials. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.
CVE-2026-35051 Crítica · 10.0 CWE-345 30/04/2026
Traefik: ForwardAuth trustForwardHeader=false allows spoofed X-Forwarded-Prefix to bypass auth
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is an authentication bypass vulnerability in Traefik's ForwardAuth middleware when trustForwardHeader=false is configured and Traefik is deployed behind a trusted upstream proxy. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.
CVE-2026-33433 Alta · 8.8 CWE-290 27/03/2026
Traefik Vulnerable to BasicAuth/DigestAuth Identity Spoofing via Non-Canonical headerField
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.42, 3.6.11, and 3.7.0-ea.3, when `headerField` is configured with a non-canonical HTTP header name (e.g., `x-auth-user` instead of `X-Auth-User`), an authenticated attacker can inject their own canonical version of that header to impersonate any identity to the backend. The backend receives two header entries — the attacker-injected canonical one is read first, overriding Traefik's non-canonical write. Versions 2.11.42, 3.6.11, and 3.7.0-ea.3 patch the issue.
CVE-2026-32695 Alta · 7.7 CWE-74 27/03/2026
Traefik has Knative Ingress Rule Injection that Allows Host Restriction Bypass
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 3.6.11 and 3.7.0-ea.2, Traefik's Knative provider builds router rules by interpolating user-controlled values into backtick-delimited rule expressions without escaping. In live cluster validation, Knative `rules[].hosts[]` was exploitable for host restriction bypass (for example `tenant.example.com`) || Host(`attacker.com`), producing a router that serves attacker-controlled hosts. Knative `headers[].exact` also allows rule-syntax injection and proves unsafe rule construction. In multi-tenant clusters, this can route unauthorized traffic to victim services and lead to cross-tenant traffic exposure. Versions 3.6.11 and 3.7.0-ea.2 patch the issue.
CVE-2026-32595 Baixa · 3.7 CWE-208 20/03/2026
Traefik: BasicAuth Middleware Timing Attack Allows Username Enumeration
Traefik is an HTTP reverse proxy and load balancer. Versions 2.11.40 and below, 3.0.0-beta1 through 3.6.11, and 3.7.0-ea.1 comtain BasicAuth middleware that allows username enumeration via a timing attack. When a submitted username exists, the middleware performs a bcrypt password comparison taking ~166ms. When the username does not exist, the response returns immediately in ~0.6ms. This ~298x timing difference is observable over the network and allows an unauthenticated attacker to reliably distinguish valid from invalid usernames. This issue is patched in versions 2.11.41, 3.6.11 and 3.7.0-ea.2.
CVE-2026-32305 Média · 5.3 CWE-287 20/03/2026
Traefik mTLS bypass via fragmented ClientHello SNI extraction failure
Traefik is an HTTP reverse proxy and load balancer. Versions 2.11.40 and below, 3.0.0-beta1 through 3.6.11, and 3.7.0-ea.1 are vulnerable to mTLS bypass through the TLS SNI pre-sniffing logic related to fragmented ClientHello packets. When a TLS ClientHello is fragmented across multiple records, Traefik's SNI extraction may fail with an EOF and return an empty SNI. The TCP router then falls back to the default TLS configuration, which does not require client certificates by default. This allows an attacker to bypass route-level mTLS enforcement and access services that should require mutual TLS authentication. This issue is patched in versions 2.11.41, 3.6.11 and 3.7.0-ea.2.
CVE-2026-29777 Média · 6.5 CWE-74 11/03/2026
Traefik has a kubernetes gateway rule injection via unescaped backticks in HTTPRoute match values
Traefik is an HTTP reverse proxy and load balancer. Prior to 3.6.10, A tenant with write access to an HTTPRoute resource can inject backtick-delimited rule tokens into Traefik's router rule language via unsanitized header or query parameter match values. In shared gateway deployments, this can bypass listener hostname constraints and redirect traffic for victim hostnames to attacker-controlled backends. This vulnerability is fixed in 3.6.10.
CVE-2026-29054 Alta · 7.5 CWE-178 05/03/2026
Traefik: lowercase `Connection` tokens can delete traefik-managed forwarded identity headers (for example, `X-Real-Ip`)
Traefik is an HTTP reverse proxy and load balancer. From version 2.11.9 to 2.11.37 and from version 3.1.3 to 3.6.8, there is a potential vulnerability in Traefik managing the Connection header with X-Forwarded headers. When Traefik processes HTTP/1.1 requests, the protection put in place to prevent the removal of Traefik-managed X-Forwarded headers (such as X-Real-Ip, X-Forwarded-Host, X-Forwarded-Port, etc.) via the Connection header does not handle case sensitivity correctly. The Connection tokens are compared case-sensitively against the protected header names, but the actual header deletion operates case-insensitively. As a result, a remote unauthenticated client can use lowercase Connection tokens (e.g. Connection: x-real-ip) to bypass the protection and trigger the removal of Traefik-managed forwarded identity headers. This issue has been patched in versions 2.11.38 and 3.6.9.
CVE-2026-26999 Alta · 7.5 CWE-400 05/03/2026
Traefik: tcp router clears read deadlines before tls forwarding, enabling stalled handshakes (slowloris doS)
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.38 and 3.6.9, there is a potential vulnerability in Traefik managing TLS handshake on TCP routers. When Traefik processes a TLS connection on a TCP router, the read deadline used to bound protocol sniffing is cleared before the TLS handshake is completed. When a TLS handshake read error occurs, the code attempts a second handshake with different connection parameters, silently ignoring the initial error. A remote unauthenticated client can exploit this by sending an incomplete TLS record and stopping further data transmission, causing the TLS handshake to stall indefinitely and holding connections open. By opening many such stalled connections in parallel, an attacker can exhaust file descriptors and goroutines, degrading availability of all services on the affected entrypoint. This issue has been patched in versions 2.11.38 and 3.6.9.
CVE-2026-26998 Média · 4.4 CWE-770 05/03/2026
Traefik: unbounded io.ReadAll on auth server response body causes OOM denial of service(DOS)
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.38 and 3.6.9, there is a potential vulnerability in Traefik managing the ForwardAuth middleware responses. When Traefik is configured to use the ForwardAuth middleware, the response body from the authentication server is read entirely into memory without any size limit. There is no maxResponseBodySize configuration to restrict the amount of data read from the authentication server response. If the authentication server returns an unexpectedly large or unbounded response body, Traefik will allocate unlimited memory, potentially causing an out-of-memory (OOM) condition that crashes the process. This results in a denial of service for all routes served by the affected Traefik instance. This issue has been patched in versions 2.11.38 and 3.6.9.
CVE-2026-25949 Alta · 7.5 CWE-400 12/02/2026
Traefik: TCP readTimeout bypass via STARTTLS on Postgres
Traefik is an HTTP reverse proxy and load balancer. Prior to 3.6.8, there is a potential vulnerability in Traefik managing STARTTLS requests. An unauthenticated client can bypass Traefik entrypoint respondingTimeouts.readTimeout by sending the 8-byte Postgres SSLRequest (STARTTLS) prelude and then stalling, causing connections to remain open indefinitely, leading to a denial of service. This vulnerability is fixed in 3.6.8.
CVE-2026-22045 Alta · 7.5 CWE-770 15/01/2026
Traefik's ACME TLS-ALPN fast path lacks timeouts and close on handshake stall
Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.35 and 3.6.7, there is a potential vulnerability in Traefik ACME TLS certificates' automatic generation: the ACME TLS-ALPN fast path can allow unauthenticated clients to tie up go routines and file descriptors indefinitely when the ACME TLS challenge is enabled. A malicious client can open many connections, send a minimal ClientHello with acme-tls/1, then stop responding, leading to denial of service of the entry point. The vulnerability is fixed in 2.11.35 and 3.6.7.
CVE-2025-66491 Média · 5.9 CWE-295 08/12/2025
Traefik has Inverted TLS Verification Logic in its ingress-nginx Provider
Traefik is an HTTP reverse proxy and load balancer. Versions 3.5.0 through 3.6.2 have inverted TLS verification logic in the nginx.ingress.kubernetes.io/proxy-ssl-verify annotation. Setting the annotation to "on" (intending to enable backend TLS certificate verification) actually disables verification, allowing man-in-the-middle attacks against HTTPS backends when operators believe they are protected. This issue is fixed in version 3.6.3.
CVE-2025-66490 Média · 6.5 CWE-436 08/12/2025
Traefik doesn't Prevent Path Normalization Bypass in Router + Middleware Rules
Traefik is an HTTP reverse proxy and load balancer. For versions prior to 2.11.32 and 2.11.31 through 3.6.2, requests using PathPrefix, Path or PathRegex matchers can bypass path normalization. When Traefik uses path-based routing, requests containing URL-encoded restricted characters (/, \, Null, ;, ?, #) can bypass the middleware chain and reach unintended backends. For example, a request to http://mydomain.example.com/admin%2F could reach service-a without triggering my-security-middleware, bypassing security controls for the /admin/ path. This issue is fixed in versions 2.11.32 and 3.6.3.